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Title: Topological phase transition and quantum spin Hall state in TlBiS{sub 2}

We have investigated the bulk and surface electronic structures and band topology of TlBiS{sub 2} as a function of strain and electric field using ab-initio calculations. In its pristine form, TlBiS{sub 2} is a normal insulator, which does not support any non-trivial surface states. We show however that a compressive strain along the (111) direction induces a single band inversion with Z{sub 2} = (1;000), resulting in a Dirac cone surface state with a large in-plane spin polarization. Our analysis shows that a critical point lies between the normal and topological phases where the dispersion of the 3D bulk Dirac cone at the Γ-point becomes nearly linear. The band gap in thin films of TlBiS{sub 2} can be tuned through an out-of-the-plane electric field to realize a topological phase transition from a trivial insulator to a quantum spin Hall state. An effective k·p model Hamiltonian is presented to simulate our first-principles results on TlBiS{sub 2}.
Authors:
;  [1] ;  [2] ;  [3]
  1. Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India)
  2. Graphene Research Centre and Department of Physics, National University of Singapore, Singapore 117542 (Singapore)
  3. Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States)
Publication Date:
OSTI Identifier:
22308472
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BISMUTH COMPOUNDS; COMPUTERIZED SIMULATION; DISPERSIONS; ELECTRIC FIELDS; ELECTRONIC STRUCTURE; HALL EFFECT; HAMILTONIANS; PHASE TRANSFORMATIONS; SPIN; SPIN ORIENTATION; STRAINS; SULFUR COMPOUNDS; SURFACES; THALLIUM COMPOUNDS; THIN FILMS; TOPOLOGY